Move CFGAS_Stream to CFX_SeekableStreamProxy

This CL moves the FGAS stream code into core/fxcrt and renames to
CFX_SeekableStreamProxy.

Change-Id: I6641fe0cca45a128ef3ec281b0b40f8d60296387
Reviewed-on: https://pdfium-review.googlesource.com/4311
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>

1 files changed, 54 insertions, 0 deletions

diff --git a/core/fxcrt/cfx_seekablestreamproxy.h b/core/fxcrt/cfx_seekablestreamproxy.h
new file mode 100644
index 0000000000..d059fb8956
--- /dev/null
+++ b/core/fxcrt/cfx_seekablestreamproxy.h
@@ -0,0 +1,54 @@
+// Copyright 2017 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
+
+#ifndef CORE_FXCRT_CFX_SEEKABLESTREAMPROXY_H_
+#define CORE_FXCRT_CFX_SEEKABLESTREAMPROXY_H_
+
+#include <algorithm>
+
+#include "core/fxcrt/cfx_retain_ptr.h"
+#include "core/fxcrt/fx_stream.h"
+#include "core/fxcrt/fx_system.h"
+
+class CFX_SeekableStreamProxy : public CFX_Retainable {
+ public:
+  enum class Pos {
+    Begin = 0,
+    Current,
+  };
+
+  template <typename T, typename... Args>
+  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
+
+  FX_FILESIZE GetLength() const { return m_pStream->GetSize(); }
+  FX_FILESIZE GetPosition() { return m_iPosition; }
+  FX_STRSIZE GetBOMLength() const { return std::max(0, m_wBOMLength); }
+  bool IsEOF() const { return m_iPosition >= GetLength(); }
+
+  void Seek(CFX_SeekableStreamProxy::Pos eSeek, FX_FILESIZE iOffset);
+  FX_STRSIZE ReadString(wchar_t* pStr, FX_STRSIZE iMaxLength, bool* bEOS);
+
+  void WriteString(const CFX_WideStringC& str);
+
+  uint16_t GetCodePage() const { return m_wCodePage; }
+  void SetCodePage(uint16_t wCodePage);
+
+ private:
+  CFX_SeekableStreamProxy(const CFX_RetainPtr<IFX_SeekableStream>& stream,
+                          bool isWriteSteam);
+  CFX_SeekableStreamProxy(uint8_t* data, FX_STRSIZE size);
+  ~CFX_SeekableStreamProxy() override;
+
+  FX_STRSIZE ReadData(uint8_t* pBuffer, FX_STRSIZE iBufferSize);
+
+  bool m_IsWriteStream;
+  uint16_t m_wCodePage;
+  FX_STRSIZE m_wBOMLength;
+  FX_FILESIZE m_iPosition;
+  CFX_RetainPtr<IFX_SeekableStream> m_pStream;
+};
+
+#endif  // CORE_FXCRT_CFX_SEEKABLESTREAMPROXY_H_